MR ARTHROGRAPHY OF THE SHOULDER - RETHINKING TRADITIONAL IMAGING PROCEDURES TO MEET THE TECHNICAL REQUIREMENTS OF MR-IMAGING GUIDANCE

OBJECTIVE. The purpose of this study was to determine the feasibility of and the appropriate technique for performance of MR imaging-guided arthrography of the shoulder. SUBJECTS AND METHODS. Thirty-eight MR im aging-guided glenohumeral joint punctures were performed using an open C-arm scanner with a vertically oriented magnetic field, adapted for interventional procedures. Two different approaches to the shoulder we re used: a modification of the traditional anterior approach (seven pr ocedures), and an anterosuperior approach (31 procedures) mimicking th e anterior arthroscopy portal. The average procedure duration was dete rmined. A retrospective review of needle mediolateral and anterioposte rior position was determined for the anterosuperior approaches. RESULT S. Average procedure duration was 21 min for the anterior approach and 12 min for the anterosuperior approach. Subjectively, needle conspicu ity was minimal with the anterior approach, contributing to prolonged imaging times. Needle visualization was much improved with the anteros uperior approach. Nine of the 31 anterosuperior procedures involved in advertent injection of the subacromial or subdeltoid bursa. At the tim e of retrospective review, the needle was too laterally or too anterio rly positioned in six of these nine patients. CONCLUSION. With conside ration of the technical demands of MR imaging guidance for interventio nal procedures, MR imaging-guided arthrography of the shoulder is feas ible. The traditional radiologic approach to the shoulder must be modi fied to provide adequate visualization of the needle. The anterosuperi or approach meets this need.